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9篇 您的检索式:作者名="Mengtian CHENG"
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1Trends in particulate matter and its chemical compositions in China from 2013–2017显示文摘Accurate determination of the atmospheric particulate matter mass concentration and chemical composition is helpful in exploring the causes and sources of atmospheric enthalpy pollution and in evaluating the rationality of environmental air quality control strategies.Based on the sampling and chemical composition data of PM2.5 in different key regions of China in the CARE-China observation network,this research analyzes the environmental air quality data released by the China National Environmental Monitoring Centre during the studied period to determine the changes in the particulate matter mass concentration in key regions and the evolution of the corresponding chemical compositions during the implementation of the Action Plan for Prevention and Control of Air Pollution from 2013-2017.The results show the following.(1)The particulate matter mass concentration in China showed a significant downward trend;however,the PM2.5 annual mass concentration in 64%of cities exceeds the New Chinese Ambient Air Quality Standard(CAAQS)GradeⅡ(GB3095-2012).The region to the east of the Taihang Mountains,the Fenhe and Weihe River Plain and the Urumqi-Changji regions in Xinjiang,all have PM2.5 concentration loading that is still high,and heavy haze pollution occurred frequently in the autumn and winter.(2)During the heavy pollution in the autumn and winter,the concentrations of sulfate and organic components decreased significantly.The mean SO42-concentration in PM2.5 decreased by 76%,12%,81%and 38%in Beijing-Tianjin-Hebei(BTH),the Pearl River Delta(PRD),the Sichuan-Chongqing region(SC)and the Fenhe and Weihe River Plain,respectively.The mean organic matter(OM)concentration decreased by 70%,44%,48%and 31%,respectively,and the mean concentration of NH4+decreased by 68%,1.6%,38%and 25%,respectively.The mean elemental carbon(EC)concentration decreased by 84%and 20%in BTH and SC,respectively,and it increased by 61%and 11%in the PRD and Fenhe and Weihe River Plain,respectively.The mean concentration of mineral and unresolved chemical components(MI)dropped by 70%,24%and 13%in BTH,the PRD and the Fenhe and Weihe River Plain,respectively.The change in the PM2.5 chemical composition is consistent with the decrease of the PM2.5mass concentration.(3)In 2015,the mean OM concentration contributions to fine particles and coarse particles were 13-46%and 46-57%,respectively,and the mean MI concentration contributions to fine particles and coarse and particles were 31-60%and 39-73%,respectively;these values are lower than the 2013 values from the key regions,which is the most important factor behind the decrease of the particulate matter mass concentration.From 2013 to 2015,among the chemical components of different particle size fractions,the peak value of the coarse particle size fraction decreased significantly,and the fine particle size fractions of SO42-,NO3-,and NH4+decreased with the decrease of the particulate matter mass concentration in different particle size fractions.The fine-particle size peaks of SO42-,NO3-and NH4+shifted from 0.65-1.1μm to the finer size range of0.43-0.65μm during the same time frame.Yuesi WANG Wenjie LI Wenkang GAO Zirui LIU Shili TIAN Rongrong SHEN Dongsheng JI Shuai WANG Lili WANG Guiqian TANG Tao SONG Mengtian CHENG Gehui WANG Zhengyu GONG Jiming HAO Yuanhang ZHANG 2019Science China Earth Sciences2019,62,12:23
2Evolution of boundary layer ozone in Shijiazhuang,a suburban site on the North China Plain显示文摘The structure of the boundary layer affects the evolution of ozone(O3), and research into this structure will provide important insights for understanding photochemical pollution.In this study, we conducted a one-month observation(from June 15 to July 14, 2016) of the boundary layer meteorological factors as well as O3 and its precursors in Luancheng County,Shijiazhuang(37°53′N, 114°38′E). Our research showed that photochemical pollution in Shijiazhuang is serious, and the mean hourly maximum and mean 8-hr maximum O3 concentrations are 97.9 ± 26.1 and 84.4 ± 22.4 ppbV, respectively. Meteorological factors play a significant role in the formation of O3. High temperatures and southeasterly winds lead to elevated O3 values, and at moderate relative humidity(40%–50%) and medium boundary layer heights(1200–1500 m), O3 production sensitivity occurred in the transitional region between volatile organic compounds(VOC) and nitrogen oxides(NOx) limitations,and the O3 concentration was the highest. The vertical profiles of O3 were also measured by a tethered balloon. The results showed that a large amount of O3 was stored in the residual layer, and the concentration was positively correlated with the O3 concentration measured the previous day. During the daytime of the following day, the contribution of O3 stored in the residual layer to the boundary layer reached 27%± 7% on average.Wei Zhao Guiqian Tang Huan Yu Yang Yang Yinghong Wang Lili Wang Junlin An Wenkang Gao Bo Hu Mengtian Cheng Xingqin An Xin Li Yuesi Wang 2019Journal of Environmental Sciences2019,31,9:15
3Characteristics of PM_(2.5) pollution in Beijing after the improvement of air quality显示文摘Following the implementation of the strictest clean air policies to date in Beijing,the physicochemical characteristics and sources of PM_(2.5) have changed over the past few years.To improve pollution reduction policies and subsequent air quality further,it is necessary to explore the changes in PM_(2.5) over time.In this study,over one year(2017-2018)field study based on filter sampling(TH-150C;Wuhan Tianhong,China)was conducted in Fengtai District,Beijing,revealed that the annual average PM_(2.5) concentration(64.8±43.1μg/m^3)was significantly lower than in previous years and the highest PM_(2.5) concentration occurred in spring(84.4±59.9μg/m^3).Secondary nitrate was the largest source and accounted for 25.7%of the measured PM_(2.5).Vehicular emission,the second largest source(17.6%),deserves more attention when considering the increase in the number of motor vehicles and its contribution to gaseous pollutants.In addition,the contribution from coal combustion to PM_(2.5) decreased significantly.During weekends,the contribution from EC and NO3−increased whereas the contributions from SO4^2−,OM,and trace elements decreased,compared with weekdays.During the period of residential heating,PM_(2.5) mass decreased by 23.1%,compared with non-heating period,while the contributions from coal combustion and vehicular emission,and related species increased.With the aggravation of pollution,the contribution of vehicular emission and secondary sulfate increased and then decreased,while the contribution of NO3−and secondary nitrate continued to increase,and accounted for 34.0%and 57.5%of the PM_(2.5) during the heavily polluted days,respectively.Xiaojuan Huang Guiqian Tang Junke Zhang Baoxian Liu Chao Liu Jin Zhang Leilei Cong Mengtian Cheng Guangxuan Yan Wenkang Gao Yinghong Wang Yuesi Wang 2021Journal of Environmental Sciences2021,33,2:14
4Source apportionment of PM_(2.5)and visibility in Jinan,China显示文摘Atmospheric extinction is impacted by the chemical composition of particles.To better understand the chemical composition of PM_(2.5)(particles with diameters of less than 2.5μm)and its relationship with extinction,one-month sampling campaigns were carried out in four different seasons from 2013 to 2014 in Jinan,China.The seasonal average concentrations of PM_(2.5)were 120.9(autumn),156.6(winter),102.5(spring),and 111.8μg/m^(3)(summer).The reconstructed PM_(2.5)chemical composition showed that sulfate,nitrate,chlorine salt,organic matter(OM),mineral dust,elemental carbon(EC)and others accounted for 25%,14%,2%,24%,22%,3%and 10%,respectively.The relationship between the chemical composition of PM_(2.5)and visibility was reconstructed by the IMPROVE method,and ammonium sulfate,ammonium nitrate,OM and EC dominated the visibility.Seven main sources were resolved for PM_(2.5),including secondary particles,coal combustion,biomass burning,industry,motor vehicle exhaust,soil dust and cooking,which accounted for 37%,21%,13%,13%,12%,3%and 1%,respectively.The contributions of different sources to visibility were similar to those to PM_(2.5).With increasing severity of air pollution,the contributions of secondary particles and coal combustion increased,while the contribution of motor vehicle exhaust decreased.The results showed that coal combustion and biomass burning were still the main sources of air pollution in Jinan.Mengtian Cheng Guiqian Tang Bo Lv Xingru Li Xinrui Wu Yiming Wang Yuesi Wang 2021Journal of Environmental Sciences2021,33,4:5
5Thermal internal boundary layer and its effects on air pollutants during summer in a coastal city in North China显示文摘The thermal internal boundary layer(TIBL) is associated with coastal pollution dispersion,which can result in high concentrations of air pollutants near the surface of the Earth. In this study, boundary layer height data which were obtained using a ceilometer were used to assess the effect of the TIBL on atmospheric pollutants in Qinhuangdao, a coastal city in North China.A TIBL formed on 33% of summer days. When a TIBL formed, the sunshine duration was 2.4 hr longer, the wind speed was higher, the wind direction reflected a typical sea breeze, and the boundary layer height was lower from 9:00 LT to 20:00 LT compared to days without a TIBL. If no TIBL formed, the average concentrations of PM_(2.5) and PM_(10) decreased with increasing boundary layer height. However, when a TIBL was observed, the average concentrations of PM_(2.5) and PM_(10) increased with increasing boundary layer height. Because the air from the sea is clean, PM_(2.5) and PM_(10) concentrations reached minimums in the daytime at 16:00 LT. After16:00 LT, the PM_(2.5) and PM_(10) concentrations increased rapidly on days when a TIBL formed,which indicated that the TIBL leads to the rapid accumulation of atmospheric pollutants in the evening. Therefore, the maximum concentrations of particulate matters were larger when a TIBL formed compared to when no TIBL was present during the night. These results indicate that it is suitable for outdoor activities in the daytime on days with a TIBL in coastal cities.Jie Wei Guiqian Tang Xiaowan Zhu Lili Wang Zirui Liu Mengtian Cheng Christoph Münkel Xin Li Yuesi Wang 2018Journal of Environmental Sciences2018,30,8:2
6The heaviest particulate air-pollution episodes occurred in northern China in January, 2013: Insights gained from observation显示文摘Dongsheng Ji Liang Li Yuesi Wang Junke Zhang Mengtian Cheng Yang Sun Zirui Liu Lili Wang Guiqian Tang Bo Hu Na Chao Tianxue Wen Hongyan Miao 2014Atmospheric Environment2014,,:1
7IRE1α regulates the PTHrP-IHH feedback loop to orchestrate chondrocyte hypertrophy and cartilage mineralization显示文摘Cartilage development is controlled by the highly synergistic proliferation and differentiation of growth plate chondrocytes,in which the Indian hedgehog(IHH)and parathyroid hormone-related protein-parathyroid hormone-1 receptor(PTHrP-PTH1R)feedback loop is crucial.The inositol-requiring enzyme 1a/X-box-binding protein-1 spliced(IRE1α/XBP1s)branch of the unfolded protein response(UPR)is essential for normal cartilage development.However,the precise role of ER stress effector IRE1α,encoded by endoplasmic reticulum to nucleus signaling 1(ERN1),in skeletal development remains unknown.Herein,we reported that loss of IRE1α accelerates chondrocyte hypertrophy and promotes endochondral bone growth.ERN1 acts as a negative regulator of chondrocyte proliferation and differentiation in postnatal growth plates.Its deficiency interrupted PTHrP/PTH1R and IHH homeostasis leading to impaired chondrocyte hypertrophy and differentiation.XBP1s,produced by p-IRE1α-mediated splicing,binds and up-regulates PTH1R and IHH,which coordinate cartilage development.Meanwhile,ER stress cannot be activated normally in ERN1-deficient chondrocytes.In conclusion,ERN1 deficiency accelerates chondrocyte hypertrophy and cartilage mineralization by impairing the homeostasis of the IHH and PTHrP/PTH1R feedback loop and ER stress.ERN1 may have a potential role as a new target for cartilage growth and maturation.Mengtian Fan Nana Geng Xingyue Li Danyang Yin Yuyou Yang Rong Jiang Cheng Chen Naibo Feng Li Liang Xiaoli Li Fengtao Luo Huabing Qi Qiaoyan Tan Yangli Xie Fengjin Guo 2024Genes & Diseases2024,11,1:0
8Progranulin regulation of autophagy contributes to its chondroprotective effect in osteoarthritis显示文摘Progranulin(PGRN)is a multifunctional growth factor involved in many physiolog-ical processes and disease states.The apparent protective role of PGRN and the importance of chondrocyte autophagic function in the progression of osteoarthritis(OA)led us to investi-gate the role of PGRN in the regulation of chondrocyte autophagy.PGRN knockout chondro-cytes exhibited a deficient autophagic response with limited induction following rapamycin,serum starvation,and IL-1b-induced autophagy.PGRN-mediated anabolism and suppression of IL-1b-induced catabolism were largely abrogated in the presence of the BafA1 autophagy inhibitor.Mechanistically,during the process of OA,PGRN and the ATG5eATG12 conjugate form a protein complex;PGRN regulates autophagy in chondrocytes and OA through,at least partially,the interactions between PGRN and the ATG5eATG12 conjugate.Furthermore,the ATG5eATG12 conjugate is critical for cell proliferation and apoptosis.Knockdown or knockout of ATG5 reduces the expression of ATG5eATG12 conjugate and inhibits the chondroprotective effect of PGRN on anabolism and catabolism.Overexpression of PGRN partially reversed this effect.In brief,the PGRN-mediated regulation of chondrocyte autophagy plays a key role in the chondroprotective role of PGRN in OA.Such studies provide new insights into the pathogen-esis of OA and PGRN-associated autophagy in chondrocyte homeostasis.Yiming Pan Yuyou Yang Mengtian Fan Cheng Chen Rong Jiang Li Liang Menglin Xian Biao Kuang Nana Geng Naibo Feng Lin Deng Wei Zheng Fengmei Zhang Xiaoli Li Fengjin Guo 2023Genes & Diseases2023,10,4:0
9Dual attention autoencoder for all-weather outdoor lighting estimation显示文摘Accurate outdoor illumination estimation is not easy due to extremely complicated sky appearance and the mutual interference of the sun and sky. In view of these challenges, we present a new deep approach for the estimation of all-weather outdoor illumination. The key to our approach is a novel dual attention autoencoder(DAA) with two independent branches to compress the sun and sky lighting information from an input HDR panorama, respectively. This enables more accurate lighting estimation as evidenced by our experiments since the mutual interference between the sun and sky can be precluded effectively. In DAA,we design the adaptive feature pyramid and the attention module to promote its accuracy in compression.We further develop a sun-sky predictor, a masked network, to learn the sun and sky lighting conditions from an Fo V-limited image. Comprehensive qualitative and quantitative experiments verify the effectiveness of our proposed approach and show its superiority over the state of the arts.Piaopiao YU Jie GUO Longhai WU Cheng ZHOU Mengtian LI Chenchen WANG Yanwen GUO 2021Science China(Information Sciences)2021,64,11:0
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